Internet Protocol (IP) Version 4 (IPv4) is a fourth revision of internet protocols used for data communication over different kinds of networks. Primarily, IPv4 is used to route traffic on the Internet and can be used to provide an Internet addressing architecture for establishing connections between network-enabled devices by providing an identification (ID) for each device.
IPv4 uses 32-bit (4-byte) IP addresses to ID each device. Accordingly, the number of IP address spaces is limited to 4,294,967,296 possible unique IPv4 addresses. With an increase in the number of network-enabled devices, the number of unique IP addresses available for use is nearly exhausted. Additionally, some IPv4 addresses have been reserved for special purposes such as private networks, multicast IPv4 addresses, and special organizations, thereby further reducing the number of available unique IP addresses.
A private network is a network that uses private IP addresses, following standards such as RFC 1918 for Internet Protocol Version 4 (IPv4), to identify devices within the network. Private IP addresses can be used for home, office, and enterprise local area networks (LANs), when globally routable addresses are not required or are not available. Since private IPv4 addresses are not globally unique, the private IPv4 addresses are not globally reachable by devices outside of the private network. As a result, direct IP connectivity is not possible between devices with private IPv4 addresses unless they are within the same private network. Additionally, direct IP connectivity is not possible between devices with public IPv4 addresses as well when the devices are behind firewalls that limit access.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.